Semi-automatic blast-gate for centrifugal compressors.



2 SHEETS-SHEET 1.

Patented June 3, 1913.

R. H. RICE. SEMI-AUTOMATIC BLAST GATE FOB CENTRIPUGAL OOMPRBSSOES.

APPLICATION FILED NOV.15, 1911.

55 Inventor: Richard H. Rice.

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Mtnesses R. H. RICE.

SEMI-AUTOMATIC BLAST GATE FOR CENTRIFUGAL COMPRESSORS.

APPLICATION FILED NOV.15,1911.

1,063,596. Patented June 3, 1913.

Z SHEETS"SHEET 2.

Fig. 2. Fig.5.

Witnesses: Inventor:

Richard H. Rice,

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UNITED STATES PATENT orrrcn.

RICHARD H. 316E, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

SEMI-AUTOMATIC BLAST-GATE F01 OENTItIlEUGAL COMPRESSORS.

Specification of Letters Patent.

Patented June 3, 1913.

Application filed November 15, 1911. Serial N 0. 660,400.

To all whom it may concern: machine and the conditions existing are the Be it known that I, Rxormao H. RICE, a same as at the beginning of the wave. Un' citizen of the United States, residing at der these conditions the reservoir above men- Lynn, county of Essex, State of Massachutioned, or capacity, contains .air at a press'etts, have invented certain'new and useful sure higher than that which the machine is 60 Improvements in Semi-Automatic Blast capable of generating and, therefore, there Gates for Centrifugal Compressors, of which must be a flow of air from the reservoir the following is a specification. through the machine and out of the inlet.

M invention relates toa gate or valve for As soon as the pressure drops in said reseruse 111 the intake pipe of a centrifugal air voir or capacity to a point below that which 66 compressor in connection with a governing the machine is capable of generating, the mechanism for controlling, its driving moflow of air is reestablished through the ma: tor. When such a compressor is employed chine and this flow of air immediately be; to supply air to a blast furnace, it is prefer-, comes somewhat larger than the average abl'y provided with an automatic regulating amount flowing, and the cycle of operation 70 mechanism which insures the delivery of a before described again takes place. predetermined volume of air per unit of The ob'ect of my invention is to provide time, the pressure varying with the condia means or checking these abnormal occurtions existing in the furnace or other apparences and to this end I locate in the intake ratus receiving said air. Thus if the conpipe of the compressor a check valvewhich 76 tents of the furnace tend to clog the twyers will stop the back flow of air referred to and thereby obstructing the flow of air, the con thereby decrease the range of pressure pulsequent tendency to reduction in volume of sations generated by the compressor. This the air actsto increase the speed of the en- Valve also prevents the back flow of air from 3,5 gine or motor driving the compressor so as affecting t e governing mechanism proper. 8D

to increase the air pressure and restore the In carrying out the invention I employ ,a desired volume. butterfly valve whose lower part is heavier When the machine is blowing into a cal than the upper so that the valve has a self pacity, that is into large reservoirs con'sistclosing tendency. The effective area of the mg of lar e pipes, stoves, etcyand operating lower part is made greater than that of the at such vo umes that the discharge vanes unupper part so that under the influence of a der the particular conditions of pressure and current of air entering the compressor said volume are not adapted to give the best eflivalve will be automatically opened to admit ciency, the machine then passes through its said air and will assume an inclined posi- Jai cycle of operation as follows :Starting at tion in the intake pipe correspondingtwith a discharge pressure lower than normal with the volume of air. passing. In case howthe machine under the control of a constant ever any back blast occurs the valve will be volume governor, a flow of air larger than shut both by its weight and the action of the the average condition, due to the said condiback current of air upon its rear surface.

.40 tions, is automatically caused to pass through In. this manner the back blast is revented the machine by the low pressure, and this fromacting upon the constant v ume govlarge flow of air is acted upon properly by ernor located on the inlet side of said valve the discharge vanes in accordance with the and all trouble from this source is obviated. general ideaof their functioning, and a The arrangement also. prevents the effect of 45 pressure is built up which becomes hi her throttling of the inlet from having any 1 than the normal; but the fact of this igh effect on the indications of the governor, the pressure having been enerated automatilatter always dealing with air under atmoscally tends to decrease e flow of air, hence pheric pressure. In making and mounting as soon as the flow of air is decreased to a the valve care should be exercised to see that 60 certain critical point, the discharge vanes it is given a sufficient unbalanced area, that m}.

cease to perform their proper function and the parts should not be too heavy and that this causes the pressure "to automatically the friction in the bearin s should be de;

' drop to the point which was assumed at the creased asmuc'h' as possib c. It sometimes beginning of the cycle. In ,other words, a. happens it is desirableto utilize this wave of pressure has passed through the butterfly ialqeisimply as asthrottling deviegi? For this purpose a lever can be attached to the valve spindle and'provided with a latch that cooperates with a. notched quadrant to enable it to be locked in the desired position. The parts are so arranged thatby means of a single bolt the valve and lever can be connected and disconnected.

In the accompanying drawings, Figure'i. is a side elevation of a portion of the intake pipe of a centrifugal compressor provided with my improved check valve Fig. 2 is a cross-section of said pipe showing the valve and itsop' rating parts, and Fig. 8 is a section of the pipe and valve at right angles to Fig. 2.

The casing 1 of the compressor has a flanged neck 2 adapted, to be attached to the flanged end of the intake pipe 3 through which the air is admitted to the compressor. Intcrposed between said neck and pipe is the valvecasing 4 which has on opposite sides the tubularnecks 5, 6 in which are received the bearings 7, S for the journals of the spindle 9. The valve 10 mounted on said spindle, being a disk adapted to fit snugly against the walls of the casing 4 when said valve is closed. The axis of the spindle passes a little above the axis of the pipe 3 and easing 4 so that the valve is unbalanced, the larger portion of its being below the spindle. The current of air passing through the pipe acts more powerfully against this part of the valve and swings it more or less open, as shown in Fig. 3. To assist in producing this action, suitable means are provided upon the front of said valve for pocketing a portion of the incoming air, such for instance as an ai'igle iron 11 forming a rib against which the air acts to hasten the opening of the valve at starting and to hold it open thereafter.

The neck 5 has a flange 12 to which is socured by bolts 13 a bracket 14. A sleeve 15 is formed on said bracket, which extends into the neck and aitords a housing for the journal bearing 7, which can thus he made of considcrahlc length. The bracket supports a dash pot 16 whose movable element 17 is connected by a rod 18 with an arm 19 on a hub 20 which is secured to the spindle 9. The dash-pot may be of any desired construction, and is arranged to permit an easy opening of the valve, but to retard its closing movements, so that it will be prevcnted from hanging when shut by a sudden back blast. In caseit is desired to use the valve as a manually actuated throttle,a lever 21 is employed that is held on the spindle by means of a nut 22- which forces a hub 23 of the lever against a shoulder 24 on the hub 20. The lei of is also [)IO"l(l0d with an arm 32 that cooperates with an arm 33 car- .ried by the hub 20 that is fast-on the valve spindle-9. The arms 32 and 33 are united by a bolt- 34. When the bolt is secured in ncense place the valve can he moved by the lever but when removed the lever has no direct control. It can, however, with its arm 32, act as a stop to limit the opening of the valve 10; this does not interfere with the automatic closing of the valve to prevent surging. The lever is provided with a latch 25 sliding in guides 26 and urged by a spring a 27 against the'periphery of a notched quadrant The quadrant is fastened to the bracket by means of bolts 29. By moving the lever, any range'of opening for the valve may be obtained within the limits of the quadrant. In case it is desired to place the valve with its spindle in an upright position, the weight of the valve will be sustained by a collar 30 on said spindle bearing upon thrust washers 31.

In operation, the compressor draws in air through the pipe 3 which acts against the unbalanced valve to open it and hold it open while the air is passing. It a back blast occurs, it acts against the rear of the valve and closes it, thereby preventing any disturbance in the speed regulator and compressor. By clamping the lever 21 to the spindle of the valve bythe bolt 34, it can be operated as a throttle to regulate the amount of air passing through the intake pipe. Under this condition there is no automatic action of the valve. of the compressor is afloat 35 forming a part of a constant volume governing mechanism. To the floatis connecteda rod 36 that extends upwardly through the intake pipe and is connected to a lever 37 that actu ates the throttle valve or other controlling device of the motor driving the compressor. To the lever is also connected a rod 38 attached to the movable member of a dashpot- 39. This constant volume governing mechanism is covered in my United States Patent 919,953, dated April 27, 1909.

In accordance with the provisions of the patent statutes, I have'described the principle of operation. of my invention, together with the apparatus which I 'now'consider to represent the best embodiment thereof;

In the intake 3 I but I desire to have it understood that the apparatus shown is only illustrative. and that the invention can be carried ontjiby other means. I

What I claim as new and desire to secure by Letters Patent of the United States, is,-

i. The combination -of'a centrifugal air compressor having an intake, a constant volumc governor located in the intake, and an automatic check valve located in the intake between the governor and the compressor and operating to prevent back blasts.

2. The combination of a centrifugal air compressor and its intake, a, constant volume governor located in the intake, and a valve located in the intake between. the governor and themompreesorsvhioh is unbalthe pi e and has a tendency to cl {a 1 pressor, and valve means located in the intake and operating to check back flow of mg adapted to open the air. e t 4. The combination with the intake .pipe

of a centrifugal air compressor, of a governing device for the compressor arranged in the intake pipe, and a butterfly valve located in the. pipe adjace'ntto the governing device and mounted upon a spindle, sai valve having the area of its portion on one side of the axis of the spindle greater than that of its portion on t e opposite side of said axis so that air flowing to the comressor tends to open the valve and air flowmg back through the compressor tends to 1 close the valve.

5. The combination with the intake pipe ofa centrifugal air compressor, of a governing device located in the intake pipe, a butterfly valve arranged in the pipe adjacent to the governing device, said valve beto the incoming air and tobe moved toward its closed position by the back flow of the air, and a dash pot for retarding the closing movements of the valve.

6. The combination with the intake pipe of a centrifu al air compressor, of a govorning device located in the intake pipe a butterfly valve arranged in the pipe or checking back flow toward the governing device, said valve being adapted to be moved by the action of the flowing air when de-T.

sired a lever adapted to be secured to the spindle of the valve, an abutment carried by t e lever for limiting the o enin of the valve by the air current, a late on t e lever, and a-notched quadrant cotiperating with the latch to hold the valve in a given relation to said device when desired.

7. The combination of a centrifugal air compressor and its intake, a constant volume overnor located in the intake, a valve also ocated in the intake between the governor and the compressor, and a means located external to the intake for moving the valve.

- 8; The combination of a centrifugal air compressor and its intake, a constant volume governor located in the intake, a butterfly valve also located in the intake between the governor and the compressor, and a lever for moving the valve to decrease the effects of back blasts of air on the governor.

9. The combination of a centrifugal air compressor and its intake, a float located in the intake that rides on the incoming cur-.

rent of air and forms a part of a governing mechanism, and a valve that closes automatically to prevent back blasts of air from the gompressor from forcing the float downwar In witness whereof, I have hereunto set my hand this thirteenth day of November,

RICHARD H. RICE.

Witnesses:

, JOHN A. MCMANUB, Jr.,

ROBERT SHAND. 

